Melahat Avci Birsin

MINERAL ELEMENT DISTRIBUTION AND ACCUMULATION PATTERNS WITHIN TWO BARLEY CULTIVARS

Growth stage effects on distribution of mineral nutrients or beneficial elements phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), chloride (Cl), iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), molybdenum (Mo), sodium (Na), silicon (Si) and nickel (Ni), and the elements bromine (Br), rubidium (Rb), strontium (Sr), barium (Ba), lanthanum (La), cerium (Ce), and uranium (U) in two barley (Hordeum vulgare L.) cultivars and how the distribution of these elements changed were determined during the 2006–2007 growing season in a field experiment. Barley plants were sampled from the field at shooting, heading, soft dough, hard dough and harvest stages, and mineral nutrients and other elements concentrations of spike, flag leaf, old leaf, and stem samples were determined by polarized energy dispersive X-ray fluorescence (PEDXRF). Distribution patterns varied considerably from element to element. At the end of the season much of the Ca, Mg, S, Si, Fe, Mn, Cu, Ni, Sr, Ba, La, Ce, and U were located in the spikes. However, much of the P, K, Zn, Cl, Na, Br, and Rb remained in the old leaves or stem.

The effect of hybrid vigor on callus induction and plant regeneration from mature embryo culture of barley (Hordeum vulgare)

The influence of hybrid vigor on callus induction, callus weight, regeneration capacity of callus, culture efficiency and number of regenerated plants from mature embryo cultures of winter barley (Hordeum vulgare L.) hybrid was studied. A total of 15 F1 hybrids and their parents were used for mature embryo culture. The statistical analysis of the results revealed that positive heterosis was noticed for all these characters except for callus weight. Plants regenerated in vitro were successfully established in soil.

Analysis of ancient DNA from in vitro grown tissues of 1600-year-old seeds revealed the species as Anagyris foetida

Seven ancient seeds, about 1600 years old, were found during an archaeological excavation in Asar Island which is located in south-western Turkey. These seeds were subjected to germination, in vitro callus induction and molecular characterization experiments to test the viability and plant origin of the seeds. Six of the seven seeds had viable seed components (such as cotyledons) and produced callus tissue in Murashige and Skoog medium supplemented with 2mgl 21 6-benzylamino purine (BAP), 0.2mgl 21 1-naphthaleneacetic acid (NAA), 20gl 21 sucrose, 2mgl 21 glycine and 7gl 21 agar, but the calli from these seeds failed to yield adventitious shoots. DNA samples from callus tissues produced by ancient seeds in vitro were of good quality. The internal transcribed spacer (ITS) region in nuclear DNA (nDNA) of ancient seeds was amplified successfully. The sequences from amplified ITS DNA products of six ancient seeds indicated that their ITS sequences matched those of Anagyris foetida after subjecting them to BLAST searches in international sequence databases (NCBI). A. foetida is a relict species endemic to the Mediterranean region and used as a herbal medicine. We believe that seed characteristics such as the very hard, extremely smooth and shiny testa, toxic anagyrine alkaloid content and their storage in a pot further improved the longevity of these ancient seeds.

Phylogenetic relationships among Triticum L. and Aegilops L. species as genome progenitors of bread wheat based on sequence diversity in trnT-F region of chloroplast DNA

Cultivated wheat, (Triticum aestivum L.), is one of the most important food crops in the world. The Aegilops L. genus is frequently utilized by plant breeders for improving the current wheat cultivars due to their close relationships. Therefore, understanding the phylogenetic relationships among the species of these genera is not only valuable for plant taxonomy, but also for plant breeding efforts. The presented phylogenetic analysis was based on the sequences of trnT-F chloroplast DNA containing three non-coding sub-regions. Twelve genotypes belonging to four species of Triticum L. genus and twenty-four genotypes belonging to eight species of Aegilops genus were used in the current study. The results postulated a close genetic relationship between diploid Aegilops species containing the BB genome and polyploid Triticum species. With the exception of Aegilops cylindrica Host (CCDD), all other Aegilops species having the CC genome were alienated from Aegilops speltoides Tausch (BB) and clustered together. These two clusters joined by a third cluster including the AA genome containing diploid Triticum species.

Callus Formation and Plant Regeneration from Cultured Embryos of Diploid and Tetraploid Winter Ryes (Secale cereale L)

The ability of immature, mature and endosperm-supported mature embryos of diploid and tetraploid winter ryes (Secale cereale L) was tested to compare the callus induction and plant regeneration. Immature embryos were obtained from field grown rye. Immature embryos were aseptically excised and placed, with the scutellum upwards, on the callus culture medium consisted of Murashige and Skoog (MS) mineral salts supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D). Mature embryos were aseptically excised the imbibed seeds and placed, scutellum up, on MS medium supplement with 2 mg l−1 2,4-D. Endosperm-supported mature embryos were moved slightly (not set free) in the imbibed mature seeds. The seeds with moved embryos were placed furrow downwards in dishes containing 8 mg l−1 2,4-D for callus induction. The developed calli and regenerated plant were maintained on hormone free MS medium. Comparison of the responses of the three explants used indicated that endosperm-supported mature embryo was the most useful explant for plant regeneration in both diploid and tetraplold ryes. This is the first report of winter ryes plants having been regenerated from endosperm-supported mature embryos.